1. Field of Invention
This invention relates to propulsion systems for spaceships, specifically, to a system which uses primarily momentum transfer to propel the spaceship instead of fuel. The "propellent" in this propulsion system consists of numerous "smart" fast-moving projectiles most of which are not carried on board the spaceship. It is this last point where this invention differs from all previous propulsion systems.
2. Discussion of Prior Art
We shall restrict the following discussion to spaceships which will carry live human crews whose intention is to return to Earth alive eventually; however, the propulsion system described herein can be used to propel one-way human crew spaceships as well as unmanned spaceships. This technique can also be used to transfer material from point to point across vast distances of space where either or both points may be in space. The material transferred may be fuel, water, raw materials, finished products or anything else we wish to transfer. We use the term spaceship to refer to any man-made device which is sent into space for any purpose, whether or not it is carrying humans.
Nearly all spaceship propulsion systems currently known involve some type of fuel which is carried on board the spaceship. Said fuel is expelled from the spaceship at some rate and velocity. The force produced by this expulsion of fuel acts on the spaceship in the opposite direction to accelerate the spaceship according to Isaac Newton's third law of motion.
There are only two "fuelless" spaceship propulsion systems which are well known; namely, starsailing, in which light pressure from a nearby star such as our Sun, pushes the spaceship which consists mostly of a huge sail. It is questionable if this method of propulsion can be used to move humans from planet to planet. The other fuelless system is the interstellar ramjet, wherein the fuel used by the spaceship is actually the hydrogen gas which exists in interstellar space. This method is of no use for travel within our Solar system.
In general the relative velocity of such a spaceship is limited by the amount of fuel carried on board and is roughly equal to the integral of the acceleration over time. At the present time there are no extraterrestrial refueling facilities, consequently current spaceships must carry fuel for the return journey as well. In fact a great deal of valuable fuel is wasted because its only use is to push the fuel that will be needed later. The net result is
(a) that current propulsion systems limit the payload to a few percent (usually less than five percent) of the total initial mass of the spaceship. Said payload includes: the crew, their food, air, waste facilities, cameras, control and communications equipment, and all other equipment needed to accomplish the goals of the mission. PA1 (b) The cost of a single space voyage is exceptionally high. PA1 (c) Due to the relatively low velocity attainable with current propulsion systems, the duration of a space voyage to the nearest planets, Mars or Venus, is excessive, perhaps as long as a year. PA1 (d) Also due to the low velocity, the ultimate range of current propulsion systems is also limited. PA1 (e) Assuming the crew doesn't succomb to boredom or claustrophobia, the long trip in a microgravity environment may severely endanger the health of the crew due to bone calcium loss. PA1 (f) Only a small crew can be accommodated which means not only a high cost per person, but also that very few people will be able to enjoy the "fantastic voyage" and political support for the project will be low.
This also leads to a number of other undesirable results: